Every night at midnight the schedule will update the forecasted weather data with observed weather data and applies a checkbook style accounting of the moisture level for each zone. Any time a zone is calculated to reach its allowed depletion, the zone will be watered.
I’m not sure where I got the “hour before it runs” bit from. But I suspect you are absolutely correct when you said
And lastly, yes… in NC and yes…this unpredictable weather…
@benbigh This happened to me in the last two weeks. I noticed my new Zoysia Palisades grass on certain spots getting brown. The weather here in the mid cities of North Richland Hills, Texas is very unpredictable that I had to force the Rachio to water.